Graph panel freezes or crashes when the graph contains a large number of notes

With a large vault, the Note Graph panel freezes or crashes during rendering. The failure happens when the whole graph is added and laid out at once in the panel; the plugin's local data cache does not prevent it.

### Steps to reproduce
1. Use a vault with several thousand notes and a substantial number of links and tags between them.
2. Open Show Note Graph.
3. Wait for the graph to render.

### Expected behavior
The panel remains responsive and the graph renders correctly.

### Actual behavior
The panel becomes unresponsive or crashes during rendering, leaving the user no choice but to close and reopen it.

Reproduce the failure with a vault containing several thousand notes and many links and tags. Trace the Note Graph panel's whole-graph rendering and layout path, including how the local data cache feeds it. Done means the graph renders correctly while the panel remains responsive without freezing or crashing.

Written by the indexing model from the issue text.